Spectral studies of niflumic acid aggregation in dissolved, solid and adsorbed states.

FTIR spectra of niflumic acid in solid state, dissolved in CCl and adsorbed on silica or alumina surface, as well as their temperature dependence, provide information about different stages of aggregation: monomers, dimers, amorphous and crystalline solid phase, as well as about perturbation of the molecule by the surface. The spectra observed are compared with those obtained by quantum mechanical calculations. The luminescence spectra are less sensitive to the aggregation, they differ mostly in the intensity, while the position of maximum at about 440 nm remains almost the same.

Effect of resonance dipole-dipole interaction on spectra of adsorbed SF6 molecules.

Adsorption of SF6 on zinc oxide and on silicalite-1 was investigated by a combination of IR spectroscopy with the calculations of spectra by means of a modernized model, developed previously for liquids. Comparison of the experimental spectra and the results of modeling shows that the complex band shapes in spectra of adsorbed molecules with extremely high absorbance are due to the strong resonance dipole-dipole interaction (RDDI) rather that the surface heterogeneity or the presence of specific surface sites. Perfect agreement between calculated and observed spectra was found for ZnO, while some dissimilarity in band intensities for silicalite-1 was attributed to complicated geometry of molecular arrangement in the channels.

Linkage isomerism of CO adsorbed on alkali halides.

Variable-temperature FTIR spectra of CO adsorbed on NaCl and KBr films are shown to reveal linkage isomerism, that is, formation of C- and O-bonded adsorption complexes with the same cationic sites. Not all of the sites can be involved in that, only the three- or four-coordinated cations located on kinks, edges, or steps of microcrystals. For NaCl, these adsorption complexes account for the high-frequency (HF) C-O stretching bands at 2175 and 2160 cm(-1).

[Etiological structure and sensitivity to antibiotics of the infection process pathogens in general surgical hospital].

The studying of the species and their sensitivity to antibiotics of mostly spread infection factors constitute one of the main trends in intrastationary infection prophylaxis. In 307 patients, suffering the infection processes of various localization, such as purulent wounds, cholecystitis, cholangitis, peritonitis etc., there were studied up the species and sensitivity to antibiotics of the microorganisms determined.

A FTIR search for linkage isomerism of CN(-) ions adsorbed on oxides and zeolites.

Adsorption of HCN and DCN was studied at 150-600 K on TiO(2), ZnO, MgO and a set of X zeolites by means of FTIR spectroscopy. At the lowest temperatures adsorption is non-dissociative and occurs on surface OH groups of oxides, cations and coordinately unsaturated oxygen atoms. Bands at 2243-2147 cm(-1) assignable to CN(-) ions start to grow in the spectra of ZnO at 170 K, at 250 K for MgO and at 300 K for TiO(2), where bands of polymeric species appear simultaneously.